Archive for November, 2007

Analyzing binaural beat CDs, and a tip for BAVSA users

Every few weeks I get a call from a user who wants to import a brainwave entrainment CD or MP3 they bought elsewhere into our program in order to change what frequencies are being used and at what times.

If only it were that easy. Once a composition has been exported from a brainwave protocol into a sound format, it becomes very challenging to reverse engineer that and determine what frequencies are being used.

It becomes even more difficult when you realize that there are many different forms of auditory brainwave entrainment – binaural beats, monaural beats, isochronic tones, audio modulation, filtering and so on. Most commercial products also “mask” the entrainment in some way, usually with nature sounds such as rain, or with music.

Simply determining what brainwave frequencies are used in a recording is hard enough, much less changing or altering those frequencies in some way.

However, some users in our community forum have found a way to do this, at least with recordings that use binaural beats. First, they use a tool called BAVSA to determine what binaural beat frequencies are being used. Then, they use audio filters (band pass) to remove the binaural beats. Later, they re-insert binaural beats of their choice, using our software.

BAVSA, which stands for “binaural beat visual analysis tool”, is a program specifically designed for analyzing binaural beat frequencies. It is the creation of Jim Peters, who also created SBaGen, which I mentioned in a recent article in the AVS Journal.

You can find BAVSA here:

BAVSA is a remarkably accurate program, but can sometimes take some fiddling with to get a clear result. This is understandable, given the complexity of many binaural beat CDs, especially those with music.

Back in June, another user and I analyzed a recording with a single binaural beat that ramped from 10 hz to 2 hz. As the beat and pitch decreased, we noticed something strange: 10 hz remained through the entire recording, and other “phantom” beats showed up in the analysis as a result.

After some experimentation, we discovered that if a binaural beat is present at a high enough volume in the first 3 seconds of the recording, BAVSA’s analysis of the rest of the track will always contain the first 3 seconds of sound.

To show you what I mean, I created a binaural beat that lasts for 5 seconds and then a minute of complete silence after that. You can use any binaural beat program to create this yourself, such as our software, cooledit or SBaGen (all will produce the same result in BAVSA).

Analyzing this in BAVSA, I skip ahead to 48 seconds. It should register silence, but instead it still shows the original binaural beat:

The Solution: To work around this problem, I insert 3-4 seconds of silence at the beginning of any sound file before analysis. We applied this fix to the 10hz/2hz sound file I mentioned above, and BAVSA accurately reported the binaural beat at the exact same time mark, without showing 10 hz or the other non-existent frequencies:

In most cases, this workaround isn’t strictly necessary, since binaural beat CDs typically don’t have tones at a high enough volume for this to matter, and many CDs fade in over 10-20 seconds, effectively eliminating the potential for a problem. This may also explain why this hasn’t been noticed before.

Still, if you want to be absolutely sure of an accurate measurement, try the above tip.

Gamma Synchrony and consciousness

Stuart Hameroff talks about the definition of consciousness, relating to gamma  synchrony, EEG spikes, quantum computing and other hot topics in the study of conscious experience.


Subconscious perception

It is daunting to realize how much the subconscious knows without telling us.

One of the most telling examples of this can be found in a fascinating condition known as “blindsight“.

As a result of certain types of brain lesions, people can lose conscious awareness of their vision. That is, they become blind. But, only consciously blind. Their eyes work and their brain still receives visual input. It is only their conscious awareness that has become disconnected from the visual input.

In people who suffer from blindsight, the subconscious can still see perfectly fine. This can be demonstrated by placing an object in front of them and asking them to make a guess about it on instinct. Is it a triangle or a square? Is it red or green? Although they cannot “see” the object, their guesses will be remarkably accurate. Much more so than random guesses from those who truly are blind. Now, if you simply asked them where the object is, they would not be able to tell you. Only if you force them to hazard a wild guess will their answers become accurate!

In many cases, your instinct is also much faster than your conscious awareness. Daniel Smilek, a neuroscience professor at the University of Waterloo, studied the speed that people were able to find a specific object among a bunch of similar objects. Kind of a like a visual search for a needle in a haystack. He found that relaxing and going on gut instinct is much more efficient than consciously searching for the target. Here is a quote from the abstract:

In Experiment 1 participants were instructed to search while either actively directing their attention to the target or by passively allowing the target to just “pop” into their minds. Results showed that passive instructions led to more efficient search on a hard task but not on an easy task.

These findings suggest that the efficiency of some difficult searches can be improved by instructing participants to relax and adopt a passive cognitive strategy

His study is entitled “Relax! Cognitive strategy influences visual search”. Cognitive Daily has an online recreation of this here (and I personally experienced very similar results on this).

Another shining example of subconscious perception is our ability to “pick up” on the mental states of other people. Maureen O’Sullivan, a psychology professor at the University of San Francisco, has spent many years studying people who have the uncanny ability to detect lies. Despite what Hollywood would have us believe, lies are often extremely hard to detect. Many people make more eye contact and fidget LESS while lying. Yet, there are a talented few among us who are incredibly accurate at distinguishing truth from a fib. Much like the blindsight phenomenon, O’Sullivan says that human lie detectors are usually completely unaware of how they do it. Due to extensive social experience, and perhaps some built-in talent, their subconscious is able to interpret a huge range of nonverbal cues to reach an accurate conclusion.

A few years ago, I met someone with a similarly impressive ability to read nonverbal signals, and spent several months working with her. Looking back, it really was an interesting encounter. But at the time it was quite nerve wracking. Similar, I imagine, to hanging around this guy:

(yes, that’s the mind-reading cop from Heroes) 

Of course, there is a time and a place for gut instinct. Certain decisions should be carefully considered and weighed. Financial decisions. Career choices. Stock picks. Buying a house. The name of your first born.

The best advice we can derive from research on intuition and the subconscious is this:

Relax! And always make a mental note of your instinct and first guess. Use that as a guide for a conscious decision.

A music concert created with the brainwaves of the audience

From an outside perspective, this “concert” would look more like a gathering of cyborgs. But for those involved it is the holy grail of audience participation – using the brainwaves of the audience to produce music.


Short term vs long term meditation on attention and delta waves

The beneficial effects of meditation on general health are well known, but what is surprising to many researchers is its positive effect on attention.

Australian Neuroscientist Dylan DeLosAngeles measured the brainwaves of a 13-person meditation group as they progressed through five different meditative states. He expected to find a brain pattern that slowly moved toward sleep, or increased Delta waves.

Instead, he found that Delta waves actually decreased. The brainwaves of these meditators indicated a calm, attentive mind, as opposed to a sluggish or dazed one. Alpha waves increased during the first states of meditation analyzed, and later decreased as the meditators moved on to other states.

Last month another study was published on the meditation-attention link, this time analyzing the effects on inexperienced students after just 5 days of meditation training.  This is unique because most of research so far has been focused on experienced meditators.

Here is what they found:

Recent studies suggest that months to years of intensive and systematic meditation training can improve attention. However, the lengthy training required has made it difficult to use random assignment of participants to conditions to confirm these findings. This article shows that a group randomly assigned to 5 days of meditation practice with the integrative body–mind training method shows significantly better attention and control of stress than a similarly chosen control group given relaxation training. The training method comes from traditional Chinese medicine and incorporates aspects of other meditation and mindfulness training. Compared with the control group, the experimental group of 40 undergraduate Chinese students given 5 days of 20-min integrative training showed greater improvement in conflict scores on the Attention Network Test, lower anxiety, depression, anger, and fatigue, and higher vigor on the Profile of Mood States scale, a significant decrease in stress-related cortisol, and an increase in immunoreactivity. These results provide a convenient method for studying the influence of meditation training by using experimental and control methods similar to those used to test drugs or other interventions.

This matches the subjective reports I’ve received from people over the years. It doesn’t take long to see a noticeable effect. This is great news for meditation newbies, but don’t discount the beneficial effects of a long-lasting daily meditation routine. Neuroscientist Richard Davidson, of the University of Wisconsin, studied both experienced and novice meditators. He found long-time meditators to be less susceptible to “attentional blink”, which means they are able to distinguish between two closely spaced objects where other people can not. He also found that extremely experienced meditators showed less brain activation in response to distracting sounds, while showing more activity than novices in regions related to concentration.